This time of year I hear that question a lot, from garden clients and from customers at Flora Grubb Gardens. Aeoniums are these beautiful rosette-forming, succulent, small shrubs and perennials. Though often called “Hens and Chicks” like the other succulent genera Echeveria and Sempervivum, Aeonium tend to have a much higher profile in the landscape and are more often called “Houseleek Trees”. They are in the crassula family, along with Jade Plants, and hail from the Canary Islands and much of northern and eastern Africa.
One of my favorite things about the word “Aeonium” is that all five vowels are used exactly once in one word. I’m a geek, I know. “Sequoia” has that going on too. There are about 35 species of Aeonium, and many many varieties have been cultivated beyond those 35. They range from ground-huggers with single rosettes to 4-foot shrubs, and the rosettes will vary from 2 to 12 inches in diameter. The climates they hail from tend to be much like ours here in California. We get warm, dry summers and moderate and wet winters, and not much of a freeze to speak of. Our climate suits them well, and they have been a mainstay in our landscapes here since about the 1920’s I believe.
So what’s going on with them right now? They should have lovely, full rosettes, exemplifying Fibonacci’s Ratio to a T. You see these plants everywhere you look in San Francisco and, indeed, around the Bay. Some look gorgeous still, but why do others look so scrappy?
Succulents aren’t exactly a plant group of their own. There are succulents among many species and genera. What makes a succulent a succulent is that it has adapted to arid or seasonally dry conditions by being able to store water for the dry season – either in its leaves (like an agave), in its trunk (like a cactus or Aeonium), or its roots (like an asparagus fern). All cacti are succulents but not all succulents are cacti, we like to say.
Back to our climate. We have dry summers. Except for fog, there is not water available in the natural landscape from April through September, for the most part. There you have it. Aeoniums, this time of year, are living on reserves. It’s exactly what they’re designed to do, and it’s exactly why they’re looking so scrappy right now. Especially if they’re in a container, where the fog has less soil surface to dampen for them. This time of year – the dry season – is dormant season for them. Just like leafy trees dropping their foliage for the winter, the succulents go dormant in the dry season. They reduce surface area through which to lose precious moisture by dropping leaves. The drier the surroundings, the more they will drop. They can live on the water in their stems with zero leaves, if they have to, turning into a barren taper to survive. When the fall rains again moisten the soil, the leaves will return and the plant will spring back to life.
That’s the beauty of it though. They don’t have to lose so many of their leaves! Just because they’re adapted to drought doesn’t mean you have to make them experience it. I’m all for Xeric gardening (letting nature be the sole water source after establishment), but if you are one who irrigates your garden you’ll notice this plant doesn’t drop all its leaves. It doesn’t have to, because it’s not experiencing the soil drying out. It can keep all the leaves it can handle evaporating through.
Another ugly-making phenomenon that’s not understood happens right before the dry season. Aeoniums make a beautiful flower, and the trigger for the flower is drought. Well, dry season, anyway. They have plentiful water to grow all winter. Come spring, they build up all the energy they can. When the triggers are right (some are drought-triggered, others are age-triggered), they flower.
It’s a bittersweet flowering, though: Aeoniums are monocarpic, meaning they have “one body”. They grow, make flowers, produce seeds, and die. It’s a beautiful flower process. The rosette of leaves will start to stretch into a spiral staircase, and a cone will start to form in the center. The cone will stretch into a cone of yellow flowers about the same diameter the rosette had been, and the leaves fall off. Eventually, the flowers go to seed and the whole thing dies off.
Most Aeoniums will have multiple branches, though, and you’ll never have flowering on all of them. The oldest ones go first. If you have a solo rosette that never formed side branches and that is starting to go to flower, it will likely be done and over if you let the whole flowering process happen. Fine and dandy if you want that, but if you want the same plant to continue on you should decapitate it to a barren stump up to 8″ high before the leaves drop off. You should get two or more new branches forming presently. You can stick that decapitated head in a vase (no water necessary) and watch it finish the flowering process over the coming weeks.
If you have an Aeonium that is looking less-than-ideal this time of year, now you know why! You can change your watering habits with it if you want it to look differently next year, or appreciate that it’s just doing its natural thing and not worry that it’s dying on you. Enjoy!